The socialite and philanthropist had long tried to live down the stains of anti-Semitic activities and Nazi associations of her father and husband before and during World War II. In her later years, a scandal erupted over a younger man who was accused of exploiting her frailty.

Liliane Bettencourt, the French heiress to the L’Oréal cosmetics fortune and a family legacy of fascist associations, whose final years were vexed by allegations that she had fallen under the sway of a younger man and given him $1.4 billion, died Wednesday at her home in the Paris suburb Neuilly-sur-Seine. She was 94.

Her death was confirmed by Jean-Paul Agon, chairman and chief executive of L’Oréal Group, on the company’s website.

L’affaire Bettencourt had captivated France since 2007, when a daughter’s lawsuit charged that Mrs. Bettencourt, ranked as the richest woman in the world, had been bamboozled by a society photographer 25 years her junior for cash, annuities, fine art and, it seemed, an island in the Seychelles. The complaint challenged her mother’s competency and led to criminal charges against the man, who was portrayed as a gigolo.

Accused of “abus de faiblesse,” or exploiting the old woman’s frailty, the photographer, François-Marie Banier, was bombarded at a trial in early 2015 by the testimony of maids, butlers, doctors and others who called him the dominating manipulator of an overmedicated, disoriented woman. They said he chose Mrs. Bettencourt’s lipstick and clothing, monitored her appointments and once suggested that she adopt him.

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Deaf and afflicted with dementia, Mrs. Bettencourt did not attend the trial. But her daughter and court-appointed guardian, Françoise Bettencourt-Meyers, told the court in the southwestern city of Bordeaux: “The strategy of Mr. Banier was not just to divide and conquer. It was to break and conquer. To break our family. It was programmed destruction.”

Banier, who faced up to three years in prison, vehemently denied the daughter’s accusations and brushed off the retainers’ criticisms with literary references to Molière and a play by Jean Genet about maids plotting against a rich employer. “These are people who take revenge for a life they don’t have,” he said.

In May 2015, the court convicted Banier of abuse and money laundering and sentenced him to three years in prison, of which six months were…